//////////////////////////////////////////////////////////////////////////
//
//  Copyright (c) 2023, Cinesite VFX Ltd. All rights reserved.
//
//  Redistribution and use in source and binary forms, with or without
//  modification, are permitted provided that the following conditions are
//  met:
//
//      * Redistributions of source code must retain the above
//        copyright notice, this list of conditions and the following
//        disclaimer.
//
//      * Redistributions in binary form must reproduce the above
//        copyright notice, this list of conditions and the following
//        disclaimer in the documentation and/or other materials provided with
//        the distribution.
//
//      * Neither the name of John Haddon nor the names of
//        any other contributors to this software may be used to endorse or
//        promote products derived from this software without specific prior
//        written permission.
//
//  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
//  IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
//  THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
//  PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
//  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
//  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
//  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
//  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
//  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
//  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
//  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
//////////////////////////////////////////////////////////////////////////

#pragma once

#include "Gaffer/Spreadsheet.h"

namespace Gaffer::PlugAlgo
{

template<typename Predicate>
std::invoke_result_t<Predicate, Plug *> findDestination( Plug *plug, Predicate &&predicate )
{
	if( !plug )
	{
		// Typically a null pointer.
		return std::invoke_result_t<Predicate, Plug *>();
	}

	if( auto destination = predicate( plug ) )
	{
		return destination;
	}

	for( const auto &output : plug->outputs() )
	{
		if( auto destination = findDestination( output, predicate ) )
		{
			return destination;
		}
	}

	if( auto cell = plug->ancestor<Spreadsheet::CellPlug>() )
	{
		if( plug == cell->valuePlug() || cell->valuePlug()->isAncestorOf( plug ) )
		{
			if( auto spreadsheet = IECore::runTimeCast<Spreadsheet>( cell->node() ) )
			{
				if( auto output = spreadsheet->outPlug()->getChild<Plug>( cell->getName() ) )
				{
					if( plug != cell->valuePlug() )
					{
						output = output->descendant<Plug>( plug->relativeName( cell->valuePlug() ) );
					}
					return findDestination( output, predicate );
				}
			}
		}
	}

	return std::invoke_result_t<Predicate, Plug *>();
}

template<typename Predicate>
std::invoke_result_t<Predicate, Plug *> findSource( Plug *plug, Predicate &&predicate )
{
	while( plug )
	{
		if( auto source = predicate( plug ) )
		{
			return source;
		}
		plug = plug->getInput();
	}

	// Typically a null pointer.
	return std::invoke_result_t<Predicate, Plug *>();
}

} // namespace Gaffer::PlugAlgo
